1. Field of the Invention
The present invention relates to a sealing system for a spherical bearing in which a spherical surface of a split inner race is supported by an inner spherical surface of an outer race.
2. Description of the Related Art
As shown in FIGS. 6 and 7, a spherical bearing 31 in which a spherical surface 33a of an inner race 33 is slidably supported by an inner spherical surface 32a of an outer race 32 has been known. In the spherical bearing 31 a shaft not shown fixed in an axial hole 33b provided on the inner race 33 is supported rotatably and oscillatory. There has been provided with a spherical bearing 31 wherein the inner race 33 is split at a given split surface 33c in such a manner that the inner race 33 is easily inserted into the inner spherical surface 32a of the outer race 32 when being assembled. Further, when sealing the spherical bearing 31 in a conventional method, a seal 35 made of silicon, nylon or rubber is hold by an annular retainer 34 made of steel while a side end portion of the retainer 34 is welded to an end surface 32b of the outer race 32 by means of an electron beam as shown in FIGS. 6 and 7.
However, when the retainer 34 holding the seal 35 is connected to both end surfaces 32b of the outer race 32, the retainer 34 is welded to each of the end surfaces 32b through a different process resulting in additional processes and time. Moreover, since the end surface 32b requires high flatness for the sealing system, processing the outer race 32 becomes more complicated. Furthermore, when the spherical bearing 31 is fixed by abutting the end surface 32b of the outer race 32 to the housing not shown, the sealing is not possible. As shown in FIGS. 6 and 7, in a structure to mount the seal 35 to the retainer 34, the seal 35 may be twisted while the inner race 33 is under a sliding operation and a gap is generated between the seal 35 and the spherical surface 33a of the inner race 33 resulting in a deterioration of the sealing function. In this case, the retainer 34 once fixed needs to be removed from the end surface 32b of the outer race 32 for welding again. And, since the sealing system is formed in such a manner that the seal 35 is extended inside an edge portion 32c of the inner spherical surface 32a of the outer race 32, the seal 35 gives a limitation to a swing angle of a shaft not shown fitted to the inner race 33 resulting in a difficulty to obtain a desired swing angle.
The present invention has been made in the light of the above, and an object of the present invention is to provide a sealing system of a spherical bearing in such a manner as to maintain a high sealing function with a simple structure and to avoid a limitation of a swing angle.
In order to attain the above object, according to a first aspect of the present invention, in a sealing system of a spherical bearing wherein spherical surfaces of a split type inner race is slidably supported by an inner spherical surface of an outer race, an annular seal groove is provided to the inner spherical surface of the outer race with a given space from an edge of the inner spherical surface of the outer race.
With this construction, the spherical bearing can be sealed in such a manner as to abut the seal fitted in the seal groove to the spherical surface of the inner race.
According to a second aspect of the present invention, a side wall of a seal groove wherein a seal is fit is bent inside.
With this construction, the seal is fixed more tightly to the seal groove by a deformation of a section of the seal groove. And, a sealing function can be improved by closely abutting the seal to the spherical surface of the inner race in such a manner that the seal is deformed.